JPS60232857A - High-speed profile milling method and device for rotatory symmetric workpiece - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention advances a grinding wheel along the rotational axis of a workpiece,
This invention relates to a method and apparatus for high-speed profile grinding of a rotationally symmetrical workpiece fixed to a grinding machine so that it can rotate about the longitudinal axis of the workpiece by displacing it in the radial direction according to the circumferential contour to be ground. .

In profile grinding of rotary bodies, grinding wheels whose external shape corresponds to the contour to be ground are conventionally used. Grinding wheels with a width similar to the contour have the disadvantage that they grind with correspondingly high radial forces under so-called "one-line contact" and, as a result, the coolant does not work optimally. In order to suppress the temperature rise of the workpiece, a relatively low cutting speed is generally used, partly due to the large weight of the grinding wheel.

As a result, machining times are relatively long, which increases the cost of the workpiece considerably.

The aim of the invention is to ensure that all workpieces can be ground carefully and in a short time, and on the other hand that the grinding wheel is centered on the longitudinal axis in such a way that it wears uniformly in successive layers along its circumference. It is an object of the present invention to provide a method and apparatus for high-speed cylindrical grinding or rotary grinding of a rotationally symmetrical workpiece rotatably fixed to a rotor.

According to the invention, an end grinding wheel with an approximately flat generatrix (contour line) or, during the grinding process, an area of finished (minimum) diameter around the workpiece and on a line perpendicular to the longitudinal axis of the workpiece ε contact at the point, and at the same time the generatrix of the grinding wheel has a clearance angle between it and the circumferential line of the grinding surface of the workpiece, so that the adjacent finished grinding surface can no longer be gripped by the grinding wheel. The above object is achieved by being guided against the surface of the workpiece to be machined.

The grinding device for carrying out the above method comprises a rotationally symmetrical workpiece rotatably fixed at both ends in a holder, carried and driven by a grinding spindle and movable along the axis of rotation of the workpiece, a grinding wheel displaceable in a radial direction according to a desired grinding profile of the workpiece, the grinding wheel having a generally flat generatrix and configured such that the grinding wheel is mounted obliquely relative to the workpiece; ing.

It is preferable that the circumferential surface of the grinding wheel is cylindrical and that the axis of the grinding wheel interposes an angle greater than O between the axis of the grinding wheel and the longitudinal axis of the workpiece to produce the above arrangement.

Preferably, the axis of the grinding wheel having a conical peripheral surface and the axis of the workpiece are twisted with respect to each other. In that case, the arrangement may be such that the axis of the grinding spindle can be deflected and adjusted horizontally and vertically with respect to the axis of the workpiece.

The expression "generally flat circumferential surface" also includes surfaces that run in a straight line or have a large radius.

The essential advantage of this proposal according to the invention is that it reduces the tool costs and considerably shortens the grinding time with very little heat generation. When using a flat grinding wheel, cooling is much more intensive than before, which not only avoids heat build-up within the workpiece, but also avoids subjecting the workpiece to extreme radial grinding pressures. I don't want it to happen. This is because, firstly, the working surfaces of the grinding wheels that respectively engage the workpiece per unit time are relatively small, and most of the grinding pressure is transmitted in the axial direction.

Unlike conventional grinding, the forces acting at right angles to the axis are only small, and these forces act only at points on the workpiece's circumference that are perpendicular to the workpiece's longitudinal axis, resulting in relatively high cutting speeds. It is possible to use Another advantage is that the grinding wheel wears evenly in a thin layer to one side. This is why one layer is removed from the periphery of the grinding wheel, and the time for subsequent resurfacing can be ascertained mathematically. If the grinding wheel is provided with a borazon coating, the service life is significantly increased.

By installing the grinding wheel obliquely or in a twisted arrangement with respect to the workpiece to be machined, a clearance angle is created between the generatrix of the grinding wheel and the circumferential line of the workpiece, and as a result, the grinding wheel is placed at the intended location. It only acts on the workpiece, but the others have space, so
It is not possible for the grinding wheel to re-grind the finished contour in a subsequent grinding process. Therefore, according to the present invention, the oblique end face of the grinding wheel acts on the workpiece depending on the desired feed depth;
The final diameter of the workpiece is ground by means of a grinding wheel exclusively in point contact, whereas the "manufacturing technology and factory (Fertigun)
gstechnikund Be-trieb ) J
According to Vol. 23, No. 3 (1973), pp. 166-171, the axis of the grinding wheel and the axis of the workpiece are parallel to each other on the same plane.
The grinding arrangement is such that the grinding wheel acts on the workpiece with two generatrices.

East German Patent No. 29342 @ specification states that the motion component approximately corresponds to manual grinding and polishing, that is, the workpiece is characterized by constant reciprocating rotational movement while changing the advancing direction of the polishing device. , an apparatus for grinding and polishing circularly symmetrical and asymmetrical thin-walled workpieces is described.

Although this publication indicates the tilted position of the polishing wheel relative to the longitudinal axis of the workpiece, it is clear that this tilted position only means that the workpiece can be polished with exactly the same intensity as by hand. . This publication does not give any instructions regarding the gradual and even wear of the grinding wheel, so as to create a clearance angle between the grinding wheel and the workpiece acting on the end face, so that constant reshaping is not necessary. .

Next, the present invention will be described in detail by way of examples based on the accompanying drawings.

The plan view in FIG. 1 shows a rotationally symmetrical rotating body, ie a workpiece 1, on which a grinding body in the form of a narrow grinding wheel 2 acts. The axis of rotation 2a of this grinding wheel 2 is turned horizontally by an angle β with respect to the longitudinal axis 4 of the workpiece. It can be seen in the front view of FIG. 2 that by redirecting the axis of rotation 2a of the grinding wheel perpendicularly to the axis 4 of the workpiece, a different crossing angle α is provided. The inclination of the grinding wheel relative to the workpiece during grinding will now be explained more clearly with reference to FIGS. 3 and 4. FIG.

According to FIGS. 3 and 4, a grinding wheel 2 having a generally flat outer circumferential surface acts at an angle around a workpiece whose circumference S is to be removed in accordance with the grinding wheel. do. Initially, a slope F is formed, by means of which the grinding wheel acts on the part of the workpiece to be removed. On the other hand, due to the special arrangement of the grinding wheel with respect to the workpiece, there is a relief angle (not shown but obvious) between the linear generatrix M of the grinding wheel and the finished grinding outer circumferential surface U of the workpiece 1, so that the circumferential surface U Once the has completed the grinding,
No longer in contact with the grinding wheel. In this case, a significant part of the pressure of the grinding wheel is derived axially through the line of FIG. 3, or the component of the grinding force directed radially is shown at 1a in FIGS. Acts on the workpiece only at the points shown.

During subsequent grinding, the end face F moves toward the free edge of the grinding wheel against the forward direction of the grinding wheel, as shown in FIG. In FIG. 4, the grinding wheel is already worn down to 80% in the form of layers.

The oblique end face of the grinding wheel is indicated by Fl in FIG.

Figures 6 to 8 show schematic diagrams of grinding wheel wear. Straight generatrix M of grinding wheel 2 and workpiece 1 that has already been ground
The relief angle formed between the outer circumferential line U and the diameter of is not shown in the figure. According to FIG. 6, the oblique end face F of the grinding wheel 2 acts on the workpiece layer B of the workpiece 1, depending on the desired grinding depth S. The radial infeed and axial movement of the grinding wheel 2 relative to the workpiece 1 is indicated by arrows. However, Figures 6 to 8
In the illustrated grinding process, not only is the diameter of the workpiece 1 reduced by twice the grinding depth, but also the grinding wheel 2 is progressively worn in layers corresponding to the grinding depth S during the grinding process. During actual grinding, the majority of the grinding force acts in the axial direction, but the radial component of this force is transmitted exclusively from the grinding wheel 2 to the workpiece 1 at point 1a. In this way, the grinding wheel 2 has a point contact with the workpiece at location 1a, or the workpiece itself is not exposed to large radial pressures. This point 1a is located on a line perpendicular to the longitudinal axis of the workpiece at the location where the workpiece 1 has just been ground by the grinding wheel. In the example shown, this is the outer circumferential line U of FIG. 7, while the peripheral portion U1 of the workpiece (FIG. 6) is to be ground.

In this way, the wear of the grinding wheel is reduced to a layer S corresponding to the grinding depth.
, so unless this layer has been completely removed, the grinding wheel should not be reconditioned or fed anew. Referring to Figures 3 and 4, this means that, unlike traditional grinding methods, there is no need for constant reshaping as long as part X or X2 of the outer circumferential surface of the grinding wheel is available for use in the grinding process. means.

The proposal according to the invention makes it possible to carry out very careful high-speed profile grinding of workpieces. This is because, unlike the known cylindrical grinding method, where more than 90% of the force acts at right angles to the axis of the workpiece, the radial force is based on the point contact between the grinding wheel 2 and the workpiece 1 at point 1a and is exclusively This is because most of the force is transmitted in the axial direction by the oblique end face.

FIGS. 9 and 10 show schematic diagrams of the arrangement of the grinding wheel relative to the workpiece. According to FIG. 9, the clearance angle α is indicated, so that the part of the grinding wheel in the area of the finished diameter of the workpiece 1 is
It can no longer engage with surfaces that have already been ground. When the grinding wheel 2 is moved in the direction of the arrow shown in Fig. 9 with respect to the rotating workpiece, the grinding wheel 2 wears out uniformly in layers along the oblique end surface. clearly indicated.

The grinding wheel 2 acts exclusively on the workpiece through point 1a to complete the finished diameter (outer circumference U), while the remaining grinding force is removed from the workpiece through the oblique end face F of the grinding wheel. It is clearly seen in the illustration in FIG. 10 that it acts on the outer periphery.

One method of profile grinding is shown in FIG. The twisted arrangement of the rotation axis 2a of the grinding body and the length l111I4 of the workpiece can be seen in this figure. In this case, a grinding machine numerically controlled by a programmable computer is used;
In this case, the axial and radial feed of the grinding wheel is also controlled by a computer program. This makes it possible to guide the grinding wheel extremely accurately according to the desired contour, so that the contour shown as an example in FIG. 5 can be machined around the workpiece without any technical effort. .

The advantages obtained by the present invention are summarized as follows.

1) Grinding time can be shortened (about 10-25%).

2) Heat generation is reduced.

3) The rotation speed of the workpiece can be increased.

4) The rotation speed of the grinding wheel can be increased.

5) The grinding wheel can be made relatively narrow.

[Brief explanation of the drawing]

Fig. 1 is a schematic plan view of the planar arrangement of the grinding body and workpiece, in which the rotating axis of the grinding body is changed horizontally to the longitudinal axis of the workpiece;
Figure shows a front view of the arrangement shown in Figure 1, with the axis of the grinding wheel reoriented perpendicular to the longitudinal axis of the workpiece; Figure 3 shows the section of Figure 1 with the grinding wheel worn by 10%. Enlarged view; Fig. 4 is a similar view to Fig. 3, with higher wear of the grinding wheel; Fig. 5 is a schematic diagram of the grinding wheel applied to a rotationally symmetrical workpiece; Fig. 6;
Figures 7 and 8 are different schematic plan views showing how the grinding wheel wears; Figure 9 is a section of the workpiece and grinding wheel where the angle of relief α is created by the inclination of the grinding wheel relative to the rotationally symmetrical workpiece; Figure: Figure 10 shows a front view of the workpiece and grinding wheel seen from arrow A in Figure 9. 1... Workpiece, 2... Grinding wheel, 2a... Grinding wheel -
Rotation axis, 4... Workpiece vertical axis, α... Relief angle, S...
・Grinding depth, "...the oblique end face of the grinding wheel,"...the part of the workpiece to be ground, M...the generatrix of the grinding wheel, U...
- Finished grinding outer circumference of the workpiece. Flo 3 10°1041 hair FI6mm

Claims (1)

[Claims] 1. Grinding so that the workpiece can rotate about its longitudinal axis by advancing the grinding wheel along the rotational axis of the workpiece and displacing it in the radial direction according to the circumferential contour to be ground. In the method of tracing and grinding a rotationally symmetrical workpiece fixed on a disk,
An end grinding wheel with a generally flat generating line that during the grinding process contacts an area of finished diameter around the workpiece only at points that are perpendicular to the longitudinal axis of the workpiece and whose generating line runs along the workpiece characterized in that it is guided relative to the workpiece surface of the workpiece in such a way that a relief angle is interposed between it and the circumferential line of the grinding surface, so that the adjacent finished grinding surface is no longer captured by the grinding wheel. A high-speed profile grinding method for rotationally symmetrical workpieces. 2. A rotationally symmetrical workpiece whose ends are rotatably fixed in a holder and which is carried and driven by a grinding spindle, movable along the axis of rotation of the workpiece and whose radius is adjusted according to the desired grinding contour of the workpiece. In a profile grinding device for a rotationally symmetrical workpiece having a grinding wheel that can be displaced in a direction,
A high-speed profile grinding device for a rotationally symmetrical workpiece, characterized in that the grinding wheel has a generally flat generatrix and is installed obliquely with respect to the workpiece. 3. The grinding device according to claim 2, wherein the circumferential surface of the grinding wheel is cylindrical, and an angle greater than zero is sandwiched between the axis of the grinding wheel and the longitudinal axis of the workpiece. . 4. The grinding device according to claim 2 or 3, wherein the axes of the grinding wheel having a conical peripheral surface and the workpiece are twisted with respect to each other.